Managing windows in listed buildings
1. Loss of existing windows
- a) An original window is a window that is contemporary to that phase of development and should only be removed if it cannot be repaired.
- b) Later window (e.g. Victorian arrangements in Georgian openings or 20th century crittall in 19th century workshops) may also be of significance if they relate to the evolution of the building and comprise a good design delivered in sound materials. Again these should only be removed if they cannot be repaired.
- c) If the window is of no significance, (1) modern (mock) replacement, (2) of poor design, (3) inferior materials, and (4) relating to a later and less significant part of the building, the windows may be considered for removed and depend on sections 2 below.
All removal of windows with require a listed building consent.
2. Replacement of windows
- a) Where an original window (see 1a above) is removed then a like-for-like (design, profile, position, materials, opening mechanism and colour finish) replacement should be reintroduced.
- b) If the window to be lost is a latter window of no significance (see 1c above), the new window should be of a design that relates back to the original window and not replicate the existing arrangement. This includes scenarios where poor quality windows have been consented and installed. This can be justified in line with more stringent policy tests introduced by Historic England from 2008 onwards and the NPPF. Evidence will need to be provided to justify the design solution proposed.
- c) Secondary glazing may be acceptable so long as their design aligns with the window itself. Double glazing is not acceptable in any part of the original listed building.
All replacement windows with require a listed building consent.
3. Repair of windows
- a) This should replicate the design, materials and mechanical operation of the window. No double glazing can be introduced.
Some small repairs may be considered diminimus and not require listed building consent. However, this should be agreed in writing by the local planning authority.
4. New openings in existing listed fabric
- a) New windows should reflect significance of elevation and it may be possible to deviate away from original design to reflect the modernity of the opening. These works are likely to be the subject of further design analysis and discussion with the local authority.
All new openings will require a listed building consent.
5. New Extensions
- a) As with new windows above, however double glazing (if handled well) may be employed, however UPVC windows will not be acceptable.
All new windows with require a listed building consent.
Further guidance is available to download from Historic England.
Of particular use are the diagrams on page 14 and 15 which identify the parts of traditional windows, how to identify the condition of timber windows pages 24 and 25, condition of metal windows pages 27, 28 and 29, as well how to repair windows (section 4), thermal upgrading (section 5) and replacement windows (section 6).